<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>

	<body>
		<script>
			// run this function when the document is loaded
			window.onload = function() {
				// create a couple of elements 
				// in an otherwise empty HTML page
				heading = document.createElement("h1");
				heading_text = document.createTextNode("Big Head!");

				heading.appendChild(heading_text);
				heading1 = document.createElement("h1");

				heading_text1 = document.createTextNode("Big Head!2112");
				heading1.appendChild(heading_text1);
				document.body.appendChild(heading);
				document.body.appendChild(heading1);
				document.body.appendChild(heading1);//子节点重复，自然不会显示
				
			}
		</script>
	</body>

</html>